X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2366148 for flyrotary@lancaironline.net; Wed, 03 Oct 2007 10:05:49 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com Received: from edward2 ([24.74.103.61]) by cdptpa-omta03.mail.rr.com with SMTP id <20071003140510.FVYE3971.cdptpa-omta03.mail.rr.com@edward2> for ; Wed, 3 Oct 2007 14:05:10 +0000 Message-ID: <001301c805c6$6ee40580$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Problem? [FlyRotary] Re: Coolant Water Pressure Date: Wed, 3 Oct 2007 10:05:19 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0010_01C805A4.E7A513F0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 This is a multi-part message in MIME format. ------=_NextPart_000_0010_01C805A4.E7A513F0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Bill,=20 You indicate you get overheating after 10-15 minutes run time. I may = have missed it, but is this at idle, max throttle or what. Also what is = your OAT. If at idle or low power then, yes what you are seeing is not = what it should be. On the other hand, if at WOT or high power settings, = then 10-15 minutes run time would be indication of a great cooling = capacity. I can not run my engine more than a minute or two at WOT on a = 80F day without temps getting into the 200F range. But, that is at = 5800-6000 rpm. At idle, the temps stabilize and I can idle all day with = safe temps. My coolant system runs with no air cushion and yes, I get a hydraulic = "lock" pressure reading of as high as 25 psi immediately upon engine = start up. After a 30 - 60 seconds of running the pressure drops down = to zero and then after a few minutes running builds back up as the = coolant warms up to operating temperatures. =20 Plenty of suggestion have been made about what to check - all good. =20 Good luck. Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.dmack.net/mazda/index.html ----- Original Message -----=20 From: Al Wick=20 To: Rotary motors in aircraft=20 Sent: Wednesday, October 03, 2007 9:30 AM Subject: [FlyRotary] Re: Coolant Water Pressure Bill, the definitive test is the one I described below. Really = encourage you to do it as described. Resist assumptions. Convert your = ideas to measurements. -al wick ----- Original Message -----=20 From: Bill Bradburry=20 To: Rotary motors in aircraft=20 Sent: Wednesday, October 03, 2007 6:08 AM Subject: [FlyRotary] Re: Coolant Water Pressure I think that I would see air under the radiator cap if I had a = compression gas leak? I never see any air.=20 To check a piston engine for head gasket leaks, you would put the = cylinder at TDC and pressurize the cylinder to about 150 lbs with = compressed air and check the radiator for air bubbles.How do you check a = rotary? I will check the pressure sender against a mechanical gage. =20 There is obviously a heating problem, but I think the pressure is = higher than it should be until just ready to boil. I shut the engine = off at 210*, and at 22+ lbs, the boiling point should be well above = 250*?? =20 Thanks for the suggestions of where to look, guys. =20 Bill B =20 -------------------------------------------------------------------------= --- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Al p Wick Sent: Tuesday, October 02, 2007 7:49 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Coolant Water Pressure =20 Your coolant reservoir should be above engine.=20 =20 1) If it is, remove two cups of air from the reservoir. Then repeat = your test.=20 2) If you now see pressure rise above 22 psi within 5 minutes of = cold start, you clearly have compression gases leaking into cooling = system or bad gage. =20 3) Air in the block is 10 times more significant than any other = cooling factor. Make darn sure you don't have any. It causes local = boiling, high temps, strange behavior. =20 Operating with two cups of air under cap is an important safety and = diagnosis advantage. Everyone should do it. With that two cups, you only = see 22 psi if you have a genuine problem. You only see 0 psi if you have = genuine problem. The pressure is then a very fast and reliable indicator = of system integrity. So two cups of air has no negative effect on system = efficiency, just a substantial improvement in safety. Only time it could = be a negative would be if your reservoir was way too small, way too low, = or flowed way too much coolant. =20 Since you describe high temps AND pressure, I suspect you have = temperature problem. =20 I deliberately overheated my engine many times so that I was = intimate with pressure and temperature patterns. Then tested various = concepts. Don't recommend you do the same. =20 -al wick =20 =20 On Tue, 2 Oct 2007 12:38:55 -0400 "Bill Bradburry" = writes: I just recently got my Renesis started again after finishing my = cowl. I seem to be getting very high coolant pressures. I can only run = the engine about 10-15 minutes before hitting the redline at 210*. My = water pressure is at 27 Lbs at that time. I only have a 22 Lb radiator = cap, so I assume that I am blowing into the recovery tank, but I have = not confirmed that. My oil temp has never exceeded about 165*. It = might have gone higher if I could have run longer??? =20 This whole water pressure thing has me a little baffled. Since = this is a closed system and the only way pressure can build is due to = the expansion of the coolant after heating???, I am confused by some = comments that have been made from time to time. I remember something = that Tracy said about his pressure would build for a time, then go to = zero. It seems to me that the pressure should correlate to the temp = pretty closely since it is a closed system??=20 =20 Can someone enlighten me a little on the science of this pressure? = It seems to me that there could be some pressure build up on the = positive side of the pump, but it would go negative on the suction side, = so the net effect of the pump should be close to zero?? =20 Also, my Renesis had only 1800 miles on it when I bought it, so I = did not have to tear it down. As a result, I am somewhat in the dark as = to how the water flows through the system. Could someone help me with = that? I had to remove the thermostat tower for height clearance , so I = made an adapter plate that takes water from the top outlet of the pump = and sends it to the radiator (double pass), then from the radiator, it = returns to the lower inlet of the pump. =20 Thanks, Bill B =20 -al wick Cozy IV powered by Turbo Subaru 3.0R with variable valve lift and = cam timing.=20 Artificial intelligence in cockpit, N9032U 240+ hours from Portland, = Oregon Glass panel design, Subaru install, Prop construct, Risk assessment = info: http://www.maddyhome.com/canardpages/pages/alwick/index.html -Al Wick Cozy IV powered by Turbo Subaru 3.0R with variable valve lift and cam = timing.=20 Artificial intelligence in cockpit, N9032U 240+ hours from Portland, = Oregon Glass panel design, Subaru install, Prop construct, Risk assessment = info: http://www.maddyhome.com/canardpages/pages/alwick/index.html ------=_NextPart_000_0010_01C805A4.E7A513F0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Bill,
 
You indicate you get overheating after 10-15 = minutes run=20 time.  I may have missed it, but is this at idle, max throttle or=20 what.  Also what is your OAT.  If at idle or low power then, = yes what=20 you are seeing is not what it should be.  On the other hand, if at = WOT or=20 high power settings, then 10-15 minutes run time would be indication of = a great=20 cooling capacity.  I can not run my engine more than a minute or = two at WOT=20 on a 80F day without temps getting into the 200F range.  But, that = is at=20 5800-6000 rpm.  At idle, the temps stabilize and I can idle all day = with=20 safe temps.
 
My coolant system runs with no air cushion and = yes, I get=20 a hydraulic "lock" pressure reading of as high as 25 psi immediately = upon engine=20 start up.  After a 30 - 60 seconds of running the pressure =  drops=20 down to zero and then after a few minutes running builds back up as the = coolant=20 warms up to operating temperatures. 
 
Plenty of suggestion have been made about what = to check -=20 all good. 
 
Good luck.
 
Ed
 
Ed Anderson
Rv-6A N494BW Rotary = Powered
Matthews,=20 NC
eanderson@carolina.rr.comhttp://www.andersonee.com
http:/= /members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.dmack.net/mazda= /index.html
----- Original Message -----
From:=20 Al Wick =
Sent: Wednesday, October 03, = 2007 9:30=20 AM
Subject: [FlyRotary] Re: = Coolant Water=20 Pressure

Bill, the definitive test is the one = I described=20 below. Really encourage you to do it as described. Resist assumptions. = Convert=20 your ideas to measurements.
 
-al wick
----- Original Message -----
From:=20 Bill Bradburry
To: Rotary motors in = aircraft=20
Sent: Wednesday, October 03, = 2007 6:08=20 AM
Subject: [FlyRotary] Re: = Coolant Water=20 Pressure

I think = that I=20 would see air under the radiator cap if I had a compression gas = leak? =20 I never see any air.

To check = a piston=20 engine for head gasket leaks, you would put the cylinder at TDC and=20 pressurize the cylinder to about 150 lbs with compressed air and = check the=20 radiator for air bubbles=85How do you check a=20 rotary?

I will = check the=20 pressure sender against a mechanical gage. =20

There is = obviously=20 a heating problem, but I think the pressure is higher than it should = be=20 until just ready to boil.  I shut the engine off at 210*, and = at 22+=20 lbs, the boiling point should be well above=20 250*??

 

Thanks = for the=20 suggestions of where to look, guys=85

 

Bill=20 B

 

From:=20 Rotary motors in = aircraft=20 [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Al p Wick
Sent: Tuesday, October 02, = 2007 7:49=20 PM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Re: = Coolant Water=20 Pressure

 

Your coolant reservoir should be above = engine.=20

 

1) If it is, remove two cups of air from = the=20 reservoir. Then repeat your test. =

2) If you now see pressure rise above = 22 psi=20 within 5 minutes of cold start, you clearly have compression gases = leaking=20 into cooling system or bad gage.

 

3) Air in the block is 10 times more = significant=20 than any other cooling factor. Make darn sure you don't have any. It = causes=20 local boiling, high temps, strange=20 behavior.

 

Operating with two cups of air under cap = is an=20 important safety and diagnosis advantage. Everyone should do it. = With that=20 two cups, you only see 22 psi if you have a genuine problem. You = only see 0=20 psi if you have genuine problem. The pressure is then a very fast = and=20 reliable indicator of system integrity. So two cups of air has no = negative=20 effect on system efficiency, just a substantial improvement in = safety. Only=20 time it could be a negative would be if your reservoir was way too = small,=20 way too low, or flowed way too much=20 coolant.

 

Since you describe high temps AND = pressure, I=20 suspect you have temperature = problem.

 

I deliberately overheated my engine many = times so=20 that I was intimate with pressure and temperature patterns. = Then tested=20 various concepts. Don't recommend you do the=20 same.

 

-al = wick

 

 

On Tue, 2 Oct 2007 12:38:55 -0400 "Bill = Bradburry"=20 <bbradburry@bellsouth.net>= =20 writes:

I just recently got = my Renesis=20 started again after finishing my cowl.  I seem to be getting = very=20 high coolant pressures.  I can only run the engine about = 10-15=20 minutes before hitting the redline at 210*.  My water = pressure is at=20 27 Lbs at that time.  I only have a 22 Lb radiator cap, so I = assume=20 that I am blowing into the recovery tank, but I have not confirmed = that.  My oil temp has never exceeded about 165*.  It = might have=20 gone higher if I could have run = longer???

 

This whole water = pressure=20 thing has me a little baffled.  Since this is a closed system = and the=20 only way pressure can build is due to the expansion of the coolant = after=20 heating???, I am confused by some comments that have been made = from time=20 to time.  I remember something that Tracy said about his pressure = would build=20 for a time, then go to zero.  It seems to me that the = pressure should=20 correlate to the temp pretty closely since it is a closed system?? =

 

Can someone = enlighten me a=20 little on the science of this pressure?  It seems to me that = there=20 could be some pressure build up on the positive side of the pump, = but it=20 would go negative on the suction side, so the net effect of the = pump=20 should be close to zero??

 

Also, my Renesis had = only 1800=20 miles on it when I bought it, so I did not have to tear it = down.  As=20 a result, I am somewhat in the dark as to how the water flows = through the=20 system.  Could someone help me with that?  I had to = remove the=20 thermostat tower for height clearance , so I made an adapter plate = that=20 takes water from the top outlet of the pump and sends it to the = radiator=20 (double pass), then from the radiator, it returns to the lower = inlet of=20 the pump.

 

Thanks,

Bill=20 B

 


-al wick
Cozy IV powered by Turbo = Subaru 3.0R=20 with variable valve lift and cam timing.
Artificial intelligence = in=20 cockpit, N9032U 240+ hours from Portland, Oregon
Glass panel design, = Subaru=20 install, Prop construct, Risk assessment=20 = info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html

-Al Wick
Cozy IV powered by Turbo Subaru 3.0R with variable = valve lift=20 and cam timing.
Artificial intelligence in cockpit, N9032U 240+ = hours from=20 Portland, Oregon
Glass panel design, Subaru install, Prop = construct, Risk=20 assessment info:
htt= p://www.maddyhome.com/canardpages/pages/alwick/index.html
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